class Solution {
    public int maxProfit(int k, int[] prices) {
        //1. 创建dp表
        //2. 初始化
        //3. 填表
        //4. 返回值
        int INF = 0x3f3f3f3f;
        int n = prices.length;
        int[][] f = new int[n][k+1];
        int[][] g = new int[n][k+1];
        for(int j = 0; j <= k; j++) f[0][j] = g[0][j] = -INF;
        f[0][0] = -prices[0];
        g[0][0] = 0;

        for(int i = 1; i < n; i++) {
            for(int j = 0; j <= k; j++) {
                f[i][j] = Math.max(f[i-1][j], g[i-1][j]-prices[i]);
                g[i][j] = g[i-1][j];
                if(j-1 >= 0) g[i][j] = Math.max(g[i-1][j], f[i-1][j-1] + prices[i]);
            }
        }

        int ret = 0;
        for(int j = 0; j <= k; j++) {
            if(ret < g[n-1][j]) ret = g[n-1][j];
        }

        return ret;
    }
}